Method and apparatus for expanding tissue

ABSTRACT

An implantable tissue expander for supporting a body tissue including a support member positioned with respect to the body tissue and adapted to expand to a support configuration, in the support configuration, the support member shaping the body tissue.

BACKGROUND OF THE INVENTION

This invention relates generally to tissue expansion, and moreparticularly, to methods and apparatus for supporting, sculpting and/orshaping tissue.

Tissue expanders, such as implants, bladders, envelopes and the like,are typically placed within the body to expand, reconstruct, orotherwise augment missing or misshapen body tissue. For example, atissue expander may be used to augment, sculpt, and support soft tissue,such as breast, penile, gluteal, and facial tissue.

Soft tissue augmentation and reconstruction, for example breastaugmentation and reconstruction, is known and has been performed byphysicians for decades. The use of silicone gel-filled implants mayprovide improved appearance, but silicone gel-filled envelopes createsafety concerns for manufacturers, physicians, and patients due topossible leaks of the silicone gel into the body. Saline-filled implantshave been used in place of silicone gel-filled implants, but have a lessnatural shape and consistency.

Another aspect in the field of breast augmentation and reconstruction isthe use of tissue expanders. Tissue expanders typically include abladder or envelope that holds a liquid, such as saline or a hydro-gel.The tissue expander is implanted under tissue, such as under the musclebelow a surgically removed breast. A small amount of liquid is added tothe envelope periodically until the desired size is reached. By addingliquid slowly over a period of weeks or months, the covering tissue isallowed to expand to accommodate its size. However, in order to changethe volume of the tissue expander a needle must be inserted into theenvelope each time.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, an implantable tissue expander for supporting a bodytissue is provided. The implantable tissue expander includes a supportmember positioned with respect to the body tissue. The support memberhas shape memory properties and is adapted to expand to a supportconfiguration. In the support configuration, the support member shapesthe body tissue.

In another aspect, an implantable tissue expander for supporting a bodytissue is provided. The implantable tissue expander includes a supportmember adapted to be positioned with respect to the body tissue in asupport configuration. A first end of the support member is positionedwith respect to a first portion of the body tissue and an opposingsecond end of the support member is positioned with respect to a secondportion of the body tissue. The first end and the second end eachtransitions into a body of the support member, which includes a biasingelement. In the support configuration, the biasing element exerts aforce at each of the first end and the second end to support the bodytissue.

In another aspect, a method for supporting a body tissue is provided.The method includes positioning at least one tissue expander withrespect to the body tissue and expanding the at least one tissueexpander to a support configuration to support and shape the bodytissue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a tissue expander positioned with respect to abreast, according to one embodiment of this invention.

FIG. 2 is a partial cross-sectional view of the tissue expander shown inFIG. 1 positioned within a catheter delivery system, according to oneembodiment of this invention.

FIG. 3 is a front view of a first tissue expander and a second tissueexpander positioned with respect to a breast, according to oneembodiment of this invention.

FIG. 4 is a front view of a tissue expander including a plurality ofsupport members positioned with respect to a breast, according to oneembodiment of this invention.

FIG. 5 is a front view of a tissue expander positioned with respect to abreast, according to one embodiment of this invention.

FIG. 6 is a front view of a tissue expander positioned with respect to abreast, according to one embodiment of this invention.

FIG. 7 shows the tissue expander of FIG. 6 positioned in a collapsedconfiguration within a catheter, according to one embodiment of thisinvention.

FIG. 8. is a side view of a tissue expander positioned with respect to abreast, according to one embodiment of this invention

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a front view of an implantable tissue expander 100 forsupporting, shaping and/or sculpting a body tissue. While the tissueexpander is described in terms of certain specific embodiments, it isnot intended to be limited to these embodiments. For example, componentsused within the tissue expander may have a variety of shapes, sizes,and/or uses. It will be apparent to one of ordinary skill in the art,however, that the tissue expander may be practiced without limitation toany specific detail presented herein. For example, tissue expander 100can be used in conjunction with a plurality of delivery systemsincluding, but not limited to, a catheter delivery system and a surgicalimplantation system.

Referring to FIG. 1, in an exemplary embodiment, a breast 102 isillustrated with tissue expander 100 positioned at a base portion 104 ofbreast 102. The invention is not limited to the expansion,reconstruction, and/or augmentation of a breast. For example, theinvention may be used to expand, reconstruct, and/or augment penile,gluteal, and/or facial tissue. Furthermore, the invention may be used ina variety of soft body tissue areas where expansion, reconstruction,and/or reconstruction is practiced.

In the exemplary embodiment, tissue expander 100 includes a supportmember 105 having a first end 106, an opposing second end 108, and abody 110 extending therebetween, as shown in FIG. 1. Tissue expander 100may have any suitable size and/or shape. In the exemplary embodiment,tissue expander 100 has a generally arcuate or semi-circular shape orconfiguration. In alternative embodiments, the shape and/or size oftissue expander 100 is selected to correspond to a shape, a size, and/orlocation of the body tissue within the patient's body. For example, inalternative embodiments, support member 105 is one of a rod, a wire, anda ribbon having flat surfaces and/or round surfaces, and having a hollowor solid cross-sectional area.

Tissue expander 100 is adapted to expand from an initial insertionconfiguration to a support configuration for supporting and/or shapingthe body tissue. In the exemplary embodiment, tissue expander 100 has acircular cross-section and is radially expandable. In one embodiment,tissue expander 100 is radially expandable between a generallyunexpanded or insertion diameter and an expanded or support diameterwhich is greater than the insertion diameter. As such, tissue expander100 is flexible and can be coupled to a catheter in a radiallycompressed configuration, i.e. the insertion configuration, forintroduction and positioning with respect to the body tissue. Uponpositioning of tissue expander 100, tissue expander 100 is expandable tothe support configuration. In one embodiment, tissue expander 100 isexpandable using a spring-like action and/or memory properties of thematerial, for example. As such, tissue expander 100 is radiallydistensible and/or deformable. In one embodiment of this invention,tissue expander 100 includes support member 105 fabricated using asuitable material having shape memory properties that are effected bychanges in temperature or that have super elastic properties. It will beunderstood that various other means for expanding or enabling theexpansion of tissue expander 100 may be employed without departure fromthe scope of this invention.

In one embodiment, tissue expander 100 including support member 105 isfabricated from any suitable biocompatible material including, withoutlimitation, suitable metal materials, such as stainless steel, platinum,gold, titanium, and alloys and/or composites thereof, as well assuitable polymeric materials. In the exemplary embodiment, tissueexpander 100 is fabricated from Nitinol which has the ability to performwell while in a spring-like configuration, and/or in a shape memoryconfiguration.

In an alternative embodiment, tissue expander 100 includes a pluralityof magnets and/or magnetic components positioned with respect to tissueexpander 100 to affect a final shape of tissue expander 100 in thesupport configuration. For example, a first magnet is positioned atfirst end 106 of support member 105 and a second magnet is positioned atopposing second end 108 to magnetically move first end 106 towards oraway from second end 108 and, thus, support and/or shape the bodytissue.

FIG. 2 is a partial cross-sectional view of tissue expander 100positioned within a catheter delivery system 150. In the exemplaryembodiment, tissue expander 100 is configured to be delivered bycatheter system 150. For example, tissue expander 100 is bendable orshapeable into an insertion configuration for positioning withincatheter delivery system 150. Catheter delivery system 150 is insertedinto the patient's body by percutaneous delivery. A guide wire is usedto advance catheter delivery system 150, depending on the location ofthe soft body tissue within the patient's body. In one embodiment,tissue expander 100 and a tissue expander 200 are introduced usingcatheter delivery system 150 and at least a portion of tissue expander100 and tissue expander 200 are aligned with each other, as shown inFIG. 3. In one embodiment, at least one radio-opaque marker is utilizedto monitor the alignment of tissue expander 100 with tissue expander200. Alternatively, tissue expander 100 is introduced using catheterdelivery system 150 and tissue expander 200 is introduced using a secondcatheter delivery system, similar to catheter delivery system 150,without using radio-opaque markers.

As shown in FIG. 2, catheter delivery system 150 includes a catheter 151forming a chamber 153. Tissue expander 100 is positionable withinchamber 153 in an insertion configuration for introduction into thedesired body tissue region or location. In the insertion configuration,tissue expander 100 is generally straight or linear. A catheter sheath152 covers at least a portion of tissue expander 100 in the insertionconfiguration for introduction into the desired body tissue region orlocation. Catheter sheath 152 forms a housing, a sleeve, a sock or asuitable assembly for surrounding and retaining tissue expander 100 inthe unexpanded or insertion configuration within catheter deliverysystem 150. As such, in the exemplary embodiment, sheath 152 is tubularin shape. In the exemplary embodiment, sheath 152 is sized to overlay atleast tissue expander 100 and catheter 151. In alternative embodiments,sheath 152 may have any suitable shape and/or size. In one embodiment,sheath 152 is a retractable. In another embodiment, sheath 152 isconfigured to move in a distal direction and a proximal direction withrespect to or along catheter 151 to aid in the deployment of tissueexpander 100. In one aspect, sheath 152 has a yield strength greaterthan an expansion force of tissue expander 100. As such, sheath 152retains tissue expander 100 in the unexpanded or insertion configurationduring delivery and introduction of tissue expander 100.

During positioning of tissue expander 100 with respect to breast 102,sheath 152 retracts to proximally release tissue expander 100. In oneembodiment, tissue expander 100 begins to expand as it exits sheath 152.In another embodiment, tissue expander 100 expands at a selectedtemperature. In yet another embodiment, a balloon is inflatable toexpand tissue expander 100. After deployment of tissue expander 100,catheter 151, including sheath 152, is withdrawn from the body tissuelocation, leaving tissue expander 100 properly positioned with respectto the body tissue.

Exemplary embodiments of tissue expanders are described below. Theembodiments described herein are illustrated with reference to thefigures wherein similar numbers indicate the same elements in allfigures. Such figures are intended to be illustrative rather thanlimiting and are included herewith to facilitate explanation of anexemplary embodiment of the tissue expander.

FIG. 3 is a front view of tissue expander 100 and a second tissueexpander 200. Tissue expander 200 is similar to tissue expander 100except as specifically set forth below. Tissue expander 100 and tissueexpander 200 are positioned generally vertically with respect toopposing side portions of breast 102 and provide support to breast 102superiorly to inferiorly.

FIG. 4 is a front view of a tissue expander 300. In the exemplaryembodiment, tissue expander 300 includes a plurality of support members302. In this embodiment, each support member 302 is similar to supportmember 105, discussed above, and connected to adjacent support members302 at opposing end portions of tissue expander 300. Each support member302 is expandable with respect to adjacent support members 302 to formtissue expander 300 for supporting and/or shaping the body tissue, asshown in FIG. 4. In one embodiment, tissue expander 300 has a shape thatis one of arcuate and semi-circular with a curvilinear cross-section. Inalternative embodiments, tissue expander 300 has a triangular shape.Tissue expander 300 is configured to be positioned in or with respect toa lower portion 304 of breast 102, as shown in FIG. 4, to support, shapeand/or sculpt breast 102.

Tissue expander 300 is flexible and can be initially coupled to acatheter delivery system, such as catheter delivery system 150, in acompressed insertion configuration and expanded within the body tissuelocation to a support configuration. Each support member 302 of tissueexpander 300 is expandable using a spring-like action and/or shapememory properties of the material, for example. In one embodiment,support members 302 include a suitable material having shape memoryproperties reactive or responsive to temperature changes. As such,support members 302 are distensible and/or deformable.

FIG. 5 is side view of a mesh tissue expander 400. In the exemplaryembodiment, tissue expander 400 has a tubular mesh configuration and isradially expandable. In one embodiment, mesh tissue expander 400 isradially expandable between a generally unexpanded or insertionconfiguration having an insertion diameter and an expanded or supportconfiguration having a support diameter which is greater than theinsertion diameter. As such, mesh tissue expander 400 is flexible andcan be initially coupled to a catheter in a radially compressedinsertion configuration and expanded within the body tissue location toa support configuration. In one embodiment, tissue expander 400 isexpandable using a spring-like action and/or shape memory properties ofthe material, for example. Tissue expander 400 includes a suitablematerial having shape memory properties reactive or responsive totemperature changes. In another embodiment, tissue expander 400 isexpandable by balloon expansion or inflation. As such, tissue expander400 is radially distensible and/or deformable. Other suitable means forexpanding or enabling the expansion of tissue expander 400 may beemployed without departure from the scope of this invention.

In one embodiment, tissue expander 400 is fabricated from Nitinol. Othersuitable biocompatible materials, including metal materials, such asstainless steel, platinum, gold, titanium, alloys and/or composites, aswell as polymeric materials can be used to fabricate tissue expander400.

FIG. 6 is a front view of a tissue expander 500. In the exemplaryembodiment, tissue expander 500 is fabricated using a suitablebiocompatible material, such as materials discussed above in referenceto tissue expanders 100 and 400. In the exemplary embodiment, tissueexpander 500 has a generally spherical shape having a hollow interior.In alternative embodiments, tissue expander 500 has a generally solidinterior. Tissue expander 500 is radially expandable between a generallyunexpanded or insertion configuration having an unexpanded or insertiondiameter and an expanded or support configuration having an expanded orsupport diameter which is greater than the insertion diameter. Tissueexpander 500 is inserted into the patient's body using a suitableinsertion instrument, such as catheter delivery system 150. After tissueexpander 500 is positioned with respect to the body tissue, as desired,tissue expander 500 expands and increases in diameter from the insertiondiameter to the desired or selected support diameter to support, sculpt,and/or shape the body tissue.

In one embodiment, tissue expander 500 is initially positioned in acollapsed position about or within a catheter 502, as shown in FIG. 7. Asheath 504 is positioned about tissue expander 500 and at least aportion of catheter 502. In the collapsed position, tissue expander 500is positioned with respect to the body tissue, as desired. In oneparticular embodiment, a suitable guide wire 506 positions tissueexpander 500. With tissue expander 500 positioned as desired, sheath 504is movable along a length of catheter 502 to expose tissue expander 500.Tissue expander 500 expands, as shown in FIG. 6, to support, sculpt,and/or shape the body tissue. In one embodiment, a balloon is used toexpand tissue expander 500. Tissue expander 500 increases in volume toexpand to a generally spherical shape having a hollow interior. Inalternative embodiments, tissue expander 500 has a generally solidinterior in the expanded configuration. Further, in alternativeembodiments, tissue expander 500 has any suitable expanded shape. Inthis embodiment, tissue expander 500 is fabricated using a Nitinolmaterial skeleton including a covering cloth. In alternativeembodiments, tissue expander 500 includes the skeleton without thecovering cloth.

In one embodiment, implantable tissue expander 600 is adaptable to bepositioned with respect to a body tissue, for example a breast 102 asshown in FIG. 8, to support, sculpt, and/or shape the body tissue.

Tissue expander 600 is flexible and can be initially coupled to acatheter delivery system, such as catheter delivery system 150, in acompressed insertion configuration and expanded within the body tissuelocation to a support configuration. Tissue expander 600 is expandableusing a spring-like action and/or shape memory properties of thematerial, for example. In one embodiment, tissue expander 600 includes asuitable material having shape memory properties reactive or responsiveto temperature changes. As such, tissue expander 600 is distensibleand/or deformable.

Tissue expander 600 includes a support member 602 adapted to bepositioned with respect to breast 102 in a support configuration, asshown in FIG. 8. In one embodiment, first end 604 of support member 602is positioned with respect to a first portion of breast 102, for examplea superior region or location 103 of breast 102. An opposing second end606 of support member 602 is positioned with respect to a second portionof the body tissue, for example an inferior or base region or location104 of breast 102. It is apparent to those skilled in the art thatsupport member 602 may be positioned in any desirable orientation orposition with respect to breast 102. For example, support member 602 maybe positioned in a generally vertical orientation or position withrespect to breast 102, as shown in FIG. 8. In an alternative embodiment,support member 602 is positioned in a generally horizontal or lateralorientation or position with respect to breast 102. In a furtherembodiment, one or more support members 602 are used in one or more of agenerally vertical, lateral and/or diagonal orientation or position tosupport, sculpt, and/or shape breast 102, as desired.

In one embodiment, first end 604 forms or includes a suitable fastener612 such as at least one hook or needle, which is inserted into the bodytissue to secure first end 604 to superior region 103 of breast 102.Similarly, a suitable fastener 612 connected to or formed by second end606 is inserted into the body tissue to secure second end 606 toinferior region 104 of breast 102. It is apparent to those skilled inthe art that fastener 612 may include any suitable fastener or connectorthat can be inserted into the body tissue and remain securely connectedto the body tissue to maintain first end 604 and second end 606 properlypositioned with respect to the body tissue.

First end 604 and second end 606 transition into a body 608 of supportmember 602. In one embodiment, body 608 includes a biasing element 610,such as a spring, a coil and/or at least one magnet, which provides aforce suitable to support, sculpt, and/or shape the body tissue, asdesired. In the support configuration, biasing element 610 exerts atension force at first end 604 and/or second end 606 to support breast102. In one embodiment, biasing element 610 is generally positioned at amid-section of support member 602 to provide a generally equal amount offorce to first end 604 and second end 606. In another embodiment,biasing element 610 is positioned on support member 602 at a suitablelocation to provide a desired or selected force to first end 604 and/orsecond end 606.

While the invention has been described in terms of various specificembodiments, those skilled in the art will recognize that the inventioncan be practiced with modification within the spirit and scope of theclaims.

1. An implantable tissue expander for supporting a body tissuecomprising: a support member positioned with respect to the body tissue,said support member having shape memory properties and adapted to moveto a support configuration, in said support configuration, said supportmember shaping the body tissue.
 2. A tissue expander in accordance withclaim 1 wherein said support member comprises a metal material havingshape memory and reactive to a temperature change.
 3. A tissue expanderin accordance with claim 1 wherein said support member comprisesNitinol.
 4. A tissue expander in accordance with claim 1 wherein, insaid support configuration, said support member exerts radial pressureagainst the body tissue to shape the body tissue.
 5. A tissue expanderin accordance with claim 1 further comprising a balloon, said ballooninflatable to expand said support member to said support configuration.6. A tissue expander in accordance with claim 1 wherein a first endportion of said tissue expander is secured to a first portion of thebody tissue and an opposing second end portion of said tissue expanderis secured to a second portion of the body tissue.
 7. A tissue expanderin accordance with claim 1 wherein said tissue expander is positionableone of laterally and vertically with respect to the body tissue.
 8. Atissue expander in accordance with claim 1 wherein said support memberincludes a biasing element exerting a tension force at each of a firstend and a second end of said support member to shape the body tissue. 9.A tissue expander assembly comprising: said implantable tissue expanderof claim 1; and a catheter configured to deliver said tissue expander toa first body tissue location.
 10. A tissue expander assembly inaccordance with claim 9 further comprising a second implantable tissueexpander positioned with respect to the body tissue and adapted toexpand to a support configuration to shape the body tissue at a secondbody tissue location.
 11. A tissue expander assembly in accordance withclaim 10 wherein said second implantable tissue expander cooperates withsaid first tissue expander to shape the body tissue.
 12. A tissueexpander assembly in accordance with claim 9 wherein said cathetercomprises a sheath, said sheath retaining said tissue expander in anunexpanded configuration within said catheter.
 13. An implantable tissueexpander for supporting a body tissue comprising: a support memberadapted to be positioned with respect to the body tissue in a supportconfiguration, a first end of said support member positioned withrespect to a first portion of the body tissue and an opposing second endof said support member positioned with respect to a second portion ofthe body tissue, each of said first end and said second endtransitioning into a body of said support member, said body including abiasing element, in said support configuration, said biasing elementexerting a force at each of said first end and said second end tosupport the body tissue.
 14. An implantable tissue expander inaccordance with claim 13 wherein said biasing element comprises one of aspring, a coil and at least one magnet.
 15. A method for supporting abody tissue, said method comprising: positioning at least one tissueexpander with respect to the body tissue; and expanding the at least onetissue expander to a support configuration to support and shape the bodytissue.
 16. A method in accordance with claim 15 further comprisingintroducing the at least one tissue expander by percutaneous deliveryusing a catheter delivery system having a sheath, the at least onetissue expander initially positioned within the sheath in an insertionconfiguration.
 17. A method in accordance with claim 16 wherein aplurality of tissue expanders are positioned with respect to the bodytissue.
 18. A method in accordance with claim 15 wherein a first tissueexpander is positioned at a first location of the body tissue and asecond tissue expander is positioned at a second location of the bodytissue, and the first tissue expander and the second tissue expandercooperate to support and shape the body tissue.
 19. A method inaccordance with claim 15 wherein the at least one tissue expander ispositioned one of laterally and vertically with respect to the bodytissue.
 20. A method in accordance with claim 15 further comprisingsecuring a first end portion of the at least one tissue expander to afirst portion of the body tissue and securing a second end portion ofthe at least one tissue expander to a second portion of the body tissue.